"Ard" <ard### [at] waikatoacnz> wrote:

>
> Note of doom 1: chances are, the source image will probably be converted
> from a PNG to a JPEG by a news server or blog site.  Doing that will either
> adjust it for a 2.2 display or drop the gamma altogether, leaving it
> suitable only for the creator's display.  To test this, I have attached a
> POV render of the following scene.  The image gamma is an obscene 30, which
> has caused all the 128/255 colour values to be elevated to 249/255.  When
> viewed in a gamma-aware viewer, the "outside" three squares are much darker
> than the inside three, and the bottom right quadrant is more orange than
> yellow.
>

OK, on my Mac's 1.8-gamma system/monitor combo (running Netscape
Communicator 4.0 as my
web browser--yeah, I know, I'm WAY behind the times ;-) --all I see are 4
very-nicely-colored squares, with just the *faintest* hint of the inner
squares. (The downloaded image is, alas, simply a jpeg...or jfif, to be
exact.) So I'm assuming that my version of Communicator is not gamma-aware.
AND/OR that my older Mac system and software doesn't even know what a .png
image is!
Interesting.

BTW, doing  a web search for "monitor gamma" brings up all sorts of useful
info.  Here are three excellent sites:

http://www.bberger.net/rwb/gamma.html

http://www.photoscientia.co.uk/Gamma.htm

http://www.cgsd.com/papers/gamma_intro.html

They explain, among other things, just WHY the Macintosh has a built-in
gamma of 1.8,  and that most "raw" CRT monitors are manufactured with a
built-in gamma of 2.5

Ken

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